Machines such as, for example, dozers, motor graders, wheel loaders, wheel tractor scrapers, and other types of heavy equipment are used to perform a variety of tasks. The completion of some of these tasks require operation on or near inclines that, if inappropriately traversed by a machine, have the potential to roll the machine over, resulting in equipment damage and possible injury to the operator. When under the direct control of a human operator, the likelihood of rollover may be estimated by the operator and appropriate avoidance measures manually implemented. However, in some situations, rollover may be difficult for the operator to anticipate and, without suitable automated safety measures in place, rollover may be unavoidable. This rollover potential may be even greater when the machine is remotely, autonomously, or semi-autonomously controlled.
Remotely controlled, autonomously controlled, and semi-autonomously controlled machines are capable of operating with little or no human input by relying on information received from various machine systems. For example, based on machine movement input, terrain input, and/or machine operational input, a machine can be controlled to remotely and/or automatically complete a programmed task. By receiving appropriate feedback from each of the different machine systems during performance of the task, continuous adjustments to machine operation can be made that help to ensure precision and safety in completion of the task. In order to do so, however, the information provided by the different machine systems should be accurate and reliable. For example, a determined inclination angle of the machine should be accurate for all ranges of inclination angles.
An exemplary system that may be used to determine the inclination angle of a machine is disclosed in U.S. Pat. No. 6,502,055 to Reiner that issued on Dec. 31, 2002 (“the '055 patent). The system of the '055 patent is capable of determining the inclination angle of a machine using an output from an accelerometer mounted on the machine to measure the acceleration ax in the forward direction due exclusively to gravity. The system of the '055 patent then calculates the inclination angle (or pitch) of the machine, θ, using the following equation:
                    θ        =                              sin                          -              1                                ⁡                      (                                          a                x                            g                        )                                              (        1        )            
Although the system of the '055 patent may be useful for determining an inclination angle of a machine, the system may not provide accurate inclination data for all inclination angles. For example, non-gravity induced accelerations may cause the inclination angle determination to be inaccurate. Further, the inclination angle determinations made using equation (1) may only be accurate for small inclination angles.
The disclosed inclination compensation system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.